By terrible I mean that I am not picking up the range of stations I once did. It reminds me of the reception you would get from using a rubber duck antenna inside the car. This is at a "engine off" state so that is not an issue. I used a Comtelco CTM-02 mount, it is utilizing Teflon coax. The spec chart does not indicate that it is double shielded. The antenna mast itself picked up great when on the mag mount.
Just to put it into further perspective, when using the mag mount (same antenna mast) on my PSR-500, I could pick up 5 NOAA stations. Now I can only pick up the closest one, and it is scratchy. I'm located about 15 miles south of Chicago, and used to pick up both CFD channels great, now it comes in scratchy and pops in and out.